Dunnage bag with double seal reusable inflation valve

ABSTRACT

A dunnage bag has an inflatable cushion and an inflation valve. The inflation valve is a flattened sleeve of thermoplastic material inserted through a seam of the inflatable cushion, with an interior sleeve portion extending into the inflatable cushion and an exterior sleeve portion extending outwardly of the inflatable cushion. A zipper seal extends across the exterior sleeve portion of the inflation valve, the zipper seal having first and second strips with releasably interengaging tongue-and-groove configuration. The inflation valve is doubly sealed, first by air pressure on the interior sleeve portion and second by closing the zipper seal. The interior sleeve portion is longer than the exterior sleeve portion, so that when it is everted, it covers the zipper seal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional application Ser. No. 61/198,824 filed on Nov. 10, 2008 and incorporated herein by reference.

TECHNICAL FIELD

The invention herein relates to a double sealed reuseable inflation valve for dunnage bags.

BACKGROUND OF INVENTION

Large dunnage bags are used for filling space between freight in shipping containers, such as trucks. Freight, often in boxes or on pallets and the like, is loaded into a truck or other shipping container, and there is often a space between the individual items of freight. Unless restrained, the freight can move about within the truck or container during transit, causing damage to the freight and/or to the truck or other container itself.

Inflatable dunnage bags are used to fill the space and secure the freight. Dunnage bags are positioned in the space between freight and are inflated in situ. The dunnage bags generally conform to the space between the individual items of freight. This holds the freight in place and cushions any minor movement thereof.

It is desirable that dunnage bags for freight applications be capable of rapid inflation. This requires an inflation valve that accommodates a relatively large inflation nozzle, so that a large volume of air can be delivered in a short time. It is also desirable that a dunnage bag be reuseable, as a substantial amount of material is involved in fabricating a dunnage bag and it is wasteful to deflate a dunnage bag by slitting it to off load freight and then using a new dunnage bag when loading freight. Reuse of a dunnage bag requires that the inflation valve open easily and sufficiently to release air quickly. Further, the inflation valve must seal reliably each time the dunnage bag is refilled.

Dunnage bags on a smaller scale are used to fill voids in cartons, thereby stabilizing products shipped therein. An inflation valve for smaller dunnage bags is a flat sleeve inserted through the edge of the bag. The sleeve accommodates an inflation probe and when the probe is withdrawn, the facing portions of the sleeve are pressed together by the air pressure within the dunnage bag to form a seal. While this seal is secure and reliable in relatively small dimensions, it tends to have slow leaks when sized to accommodate a relatively large inflation probe, e.g., on the order of two to three inches in diameter, or when it is reused many times.

Other seals for large dunnage bags are more complex and expensive, and are not easily adapted for use on dunnage bags made of thermoplastic materials. These other seals typically include removable sealing caps, requiring a threaded neck being attached to the dunnage bag as a part of the inflation valve.

Therefore, there is a need for an improved inflation valve that accommodates large probes, seals well, and is reuseable.

SUMMARY OF THE INVENTION

A principal object of the invention herein is to provide an improved inflation valve for dunnage bags and cushions.

Another object of the invention herein is to provide an improved inflation valve for large dunnage bags, wherein the inflation valve accommodates large probes.

A further object of the invention herein is to provide an inflation valve with improved sealing.

It is also an object of the invention herein to provide an inflation valve that reliably reseals throughout multiple uses.

In carrying out the invention herein, a dunnage bag is provided comprising an inflatable cushion fabricated of thermoplastic sheet material and having at least one edge along which two sheets of the thermoplastic sheet material are joined together at a seam. An inflation valve in the form of a flattened sleeve of thermoplastic material is inserted through the seam with the sheets of the inflatable cushion adhered to the exterior of the flattened sleeve. An interior sleeve portion of the inflation valve extends into the inflatable cushion and an exterior sleeve portion of the inflation valve extends outwardly from the inflatable cushion. A zipper seal having aligned interengaging rib and groove configuration is deployed across the end of the exterior portion of the flattened sleeve. An inflation probe may be inserted through the flattened sleeve when the zipper seal is in its open position to inflate the inflatable cushion. After inflation, the inflation probe is withdrawn and the interior portion of the flattened sleeve is pressed together by air pressure to form a primary seal of the inflation valve and the zipper seal is closed to provide a secondary seal.

According to additional aspects of the invention, the interior sleeve portion of the inflation valve is sufficiently long that, when everted through the exterior sleeve portion of the inflation valve, the interior portion of the sleeve covers the tongue and groove configurations of the zipper seal, protecting them from dirt and damage and preserving them for reuse.

Another aspect of the invention includes providing the inflation valve sleeve in a sufficiently large dimension to accommodate a relatively large inflation probe, which may be on the order of two or more inches in diameter.

Other and more specific objects and features of the invention herein will in part be apparent to those skilled in the art and will in part appear in the following detailed description and the claims, taken together with the drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a dunnage bag according to the invention, herein,

FIG. 2 is a fragmentary sectional view of the dunnage bag of FIG. 1, taken along the lines 2-2 of FIG. 1, and including an inflation probe;

FIG. 3 is a fragmentary sectional view of the dunnage bag of FIG. 1, taken along the lines 2-2 of FIG. 1, showing the inflation valve of a dunnage bag in its sealed condition; and

FIG. 4 is a fragmentary sectional view of the dunnage bag of FIG. 1, shown with the inflation valve thereof open for deflation and storage.

The same reference numerals refer to the same elements throughout the various figures.

DETAILED DESCRIPTION OF INVENTION

With reference to FIGS. 1-4, an inflatable dunnage bag 1 having an inflatable cushion 10 and an inflation valve 20 is shown. The inflatable cushion 10 is fabricated of thermoplastic polymer sheet material. The polymer may be polyethylene, such as metallocene-based low density polyethylene, or other polymers or coated extrusions of various polymers, as is well known in the art. A preferred polymer for the cushion 10 is 6-7 mil. LDPE. The inflatable cushion 10 is preferably fabricated of thermoplastic polymer sheet material formed as tube stock, which provides first and second sheets 12, 14 of the inflatable cushion 10 between folded side edges 13 and 15. The first and second sheets of the folded tube stock are secured together by end seams 16 and 18, with the end seam 18 mounting the inflation valve 20 as more fully described below. The inflatable cushion 10 is provided in a relatively large size, e.g., on the order of three to four feet wide and five to eight feet long in order to adapt it for use as a dunnage bag for freight containers, such as trucks. The inflatable cushion may also be fabricated of sheet stock, with appropriate seams.

The inflation valve 20 is also fabricated of polymer tube stock in the form of a flattened sleeve, having folded side edges 22 and 24. The polymer may LDPE. The flattened configuration provides the inflation valve 20 with a top valve layer 26 and a lower valve layer 28. As best seen in FIGS. 2-4, the seam 18 of the inflatable cushion 10 has portions 18 a and 18 b crossing the inflation valve 20, with seam portion 18 a securing upper valve layer 26 and the upper sheet 12 of the inflatable cushion 10 together and the seam portion 18 b securing the lower valve layer 18 and the lower sheet 14 of the inflatable cushion 10 together. A heat resistant strip 30 is provided on the inside of the upper valve layer 26, so that the valve layers 26 and 28 are not secured together as the seam portions 18 a and 18 b are formed. This is not necessary if the sheets are secured together by other means, such as bonding.

The inflation valve 20 has a first interior sleeve portion 32 that extends from the seam 18 into the inflatable cushion 10 to an end 34. The inflatable valve 20 has an exterior sleeve portion 36 that extends outwardly from the seam 18 to an outside end 38.

A zipper seal 40 is deployed across the exterior sleeve portion 36, adjacent its exterior end 38. The zipper seal 40 has a first strip 42 on upper valve layer 26 including at least one rib 44 that extends from the surface of the first strip 42, and a second strip 50 on lower valve layer 28 opposite the first strip 42. The first and second strips 42 and 50 are preferably respectively integral with the first and second layers 26, 28 of the inflation valve 20. The second strip 50 includes at least two ribs 52 and 53 that extend from the surface of the second strip 50 and define groove 54 therebetween, and ribs 52, 53 and are respectively offset from and flank the rib 44 of the first strip 42 such that the first and second strips 42, 50 may be sealingly interengaged by forcing rib 44 into groove 54. In the zipper seal 40 used herein, the first strip 42 has three ribs, 44, 45 and 46, defining grooves 47, 48 and the second strip 50 has two ribs 52 and 53 which flank the central rib 44 of strip 42. The two ribs 52, 53 are themselves respectively inserted in grooves 47, 48 flanked by the ribs 44, 45, 46 of strip 42 when the zipper seal 40 is secured is closed as shown in FIG. 3. Suitable zipper seals may be obtained from Com-Pac International, Inc. of Carbondale, Ill.

In the dunnage bag 1, the inflation valve 20 may have a flattened width W of approximately 4 inches to accommodate a relatively large inflation probe 60, seen in FIG. 2. Additionally, the interior sleeve portion 32 of the inflation valve 20 has a length Li of approximately 3 inches and the exterior sleeve portion 36 has a length Le of approximately 2 inches. Thus, the interior sleeve portion 32 is longer than the exterior sleeve portion 36 so that the interior sleeve portion 32 may be everted to cover the first and second strips 42, 50 of the zipper seal 40, as is shown in FIG. 4.

With reference to FIG. 2, the dunnage bag 1 is inflated by inserting an inflation probe 60 through the open inflation valve 20 and introducing air into the inflatable cushion 10. The inflation valve 20 accommodates the inflation probe 60 having a diameter of 2 inches or more, and preferably 2½ to 3 inches, so that a large volume of air may be introduced rapidly into the inflatable cushion 10.

When the inflatable cushion 10 is inflated to the desired volume and pressure, the inflation probe 60 is removed and the inflation valve 20 performs a two-part sealing function. With reference to FIG. 3, the upper valve layer 26 and lower valve layer 28 of the interior sleeve portion 32 of the inflation valve 20 are pressed together by the pressurized air within the inflatable cushion 10. This provides a good seal; however, this seal may have minor leakage due to a variety of factors, including whether the upper valve layer 26 and lower valve layer 28 are perfectly aligned and flat between the side edges 22 and 24 of the inflation valve 20, whether any other distortion occurred as the inflation probe was removed, whether any dirt, debris, or foreign matter became deposited between the upper valve layer 26 and the lower valve layer 28, whether any minor damage occurred to the valve layers 26, 28 due to multiple reuses, or because of other factors. It should be noted that this type of leakage is more likely to occur in the large inflation valve 20 used for dunnage bag 1 and accommodating a relatively large inflation probe 60, and when the inflation valve 20 is reused many times.

The second sealing function is provided by the zipper seal 40, which is closed as shown in FIG. 3. The zipper seal 40 is not reliably effective if subjected to large separating forces, and therefore cannot be used as a primary seal for a dunnage bag inflation valve. However, the primary seal formed by the interior sleeve portion 32 of the inflation valve 20 described above protects the zipper seal from high pressure separating forces, and the zipper seal 40 performs well in containing whatever small leakage and pressure that might develop behind the primary seal provided by the interior sleeve portion of inflation valve 20.

FIG. 4 illustrates the configuration of the inflation valve 20 in deflating the inflatable cushion 10 and in storing the dunnage bag 1 between uses. The interior sleeve portion 32 is everted, which releases the primary sealing function illustrated in FIG. 3 and permits inflation air to escape rapidly. The interior sleeve portion 32 is preferably sufficiently long that, when everted, it covers the first and second strips 42, 46 and the ribs and grooves thereof of the zipper valve 40. This is useful in protecting the ribs and grooves from accumulating dirt and debris between uses, while leaving the inflation valve 20 open so that the deflated dunnage bag 1 may be fully flattened for storage.

And although the inflatable cushion 10 and inflation valve 20 have been shown and described in a size useful for freight dunnage bags, it will be appreciated that the double sealing function of the inflation valve 20 may also be utilized with smaller scale inflation valves used in smaller sized dunnage bags, also sometimes referred to as inflatable packaging cushions or airbags, when a very secure seal is desired and when reuse is also contemplated.

Accordingly, a dunnage bag has been shown and described which admirably achieves the objects of the invention. It will be appreciated by those skilled in the art that various changes may be made with departing from the spirit and scope of the invention which is limited only by the following claims. 

1. A dunnage bag comprising: a) an inflatable cushion fabricated of thermoplastic sheet material and having at least one edge along which two sheets of the thermoplastic sheet material forming the inflatable cushion are joined together by a seam; b) an inflation valve having a flattened sleeve of thermoplastic material inserted through the seam of the inflatable cushion with the two sheets of the inflatable cushion respectively adhered to the upper and lower layers of the flattened sleeve of thermoplastic material, wherein an interior sleeve portion extends into the inflatable cushion from the seam and an exterior sleeve portion extends outwardly from the seam of the inflatable cushions; and c) a zipper seal extending across the exterior sleeve portion of the inflation valve, adjacent the end thereof, the zipper seal having first and second strips with releasably interengaging rib and groove configuration, wherein an inflation probe may be inserted through the inflation valve for inflating the inflatable cushion, and upon the withdrawal of the inflation probe, the interior sleeve portion of the inflation valve forms a primary seal and the zipper seal is closed to provide a secondary seal.
 2. A dunnage bag as defined in claim 1, wherein the interior sleeve portion of the inflation valve is sufficiently long to cover the zipper seal when everted through the exterior sleeve portion of the inflation valve.
 3. A dunnage bag as defined in claim 2, wherein the first and second strips of the zipper seal are respectively integral with the upper and lower layers of the flattened sleeve of the inflation valve.
 4. A dunnage bag as defined in claim 3, wherein one of the first and second strips of the zipper seal has at least one central rib and the other of the first and second zipper strips has at least two ribs which flank the central rib when the zipper seal is closed.
 5. A dunnage bag as defined in claim 4, wherein one of the first and second zipper strips has two additional ribs flanking the central rib, wherein the two ribs of the other of the first and second zipper strips are respectively captured between the central rib and a flanking rib when the zipper seal is closed.
 6. A dunnage bag as defined in claim 1, wherein one of the first and second strips of the zipper seal has at least one central rib and the other of the first and second zipper strips has at least two ribs which flank the central rib when the zipper seal is closed.
 7. A dunnage bag as defined in claim 6, wherein one of the first and second zipper strips has two additional ribs flanking the central rib, wherein the two ribs of the other of the first and second zipper strips are respectively captured between the central rib and a flanking rib when the zipper seal is closed.
 8. A dunnage bag as defined in claim 1, wherein the inflatable cushion is generally rectangular and has a width of at least three feet and a length of at least five feet.
 9. A dunnage bag as defined in claim 8, wherein the inflation valve has a width of at least three inches.
 10. A dunnage bag as defined in claim 9, wherein the interior sleeve portion of the inflation valve is sufficiently long to cover the zipper seal when everted through the exterior sleeve portion of the inflation valve. 